1. Field of the Invention
The present invention relates to continuous motion therapy systems. In particular, the present invention relates to safety features for a continuous motion therapy system.
2. Description of the Prior Art
In recent years there has been an increasing awareness of the advantages of mobilization of joints as part of the orthopedic care which follows an injury, an illness or surgical procedure. A joint can stiffen rapidly as a result of immobilization, and in many cases, extensive therapy is required in order to regain full use of a joint after it has stiffened.
Active motion of a joint occurs when the patient has sufficient muscle strength to flex or extend the limb without the need for external applied force. In contrast, passive motion of a joint involves the use of an external force to flex and extend the limb to induce motion. Continuous passive motion of a joint following injury, illness or surgery has been found to reduce post-operative pain, decreased adhesions, decreased muscle atrophy, and enhance the speed of recovery, while minimizing other risks of immobilization such as venous stasis, thromboembolism and post-traumatic osteopenia.
Continuous motion systems for providing continuous motion therapy are known and commercially available. One such system is disclosed in the Berner et al. U.S. Pat. No. 4,566,440. It is also known to aid the continuous motion provided by the systems with neuromuscular stimulation (NMS). A system of this type is disclosed in Wright et al. U.S. Pat. No. 4,520,827. Continuous motion systems such as the types discussed above have proven to be both safe and effective. There is, however, always room for additional safety features.